Isolation and identification of feline calicivirus and feline herpesvirus in Southern Brazil

Abstract

Feline calicivirus (FCV) and feline herpesvirus type 1 (FHV-1) are the two primary causes of upper respiratory tract disease in cats. The aim of this study was to demonstrate the distribution of FCV and FHV-1 among the feline population of several counties in Rio Grande do Sul State, Brazil. To this end, conjunctival and nasal swabs were collected from 302 cats from different locations, including households, breeding catteries, veterinary clinics, animal hospitals and experimental research facilities. The samples were collected between July 2006 to June 2009. The virus isolation was performed in CRFK cells and, subsequently, the identification was confirmed by PCR. FCV, FHV-1, or both were isolated from 55 cats from 28 different locations. FCV alone was isolated from 52.7% (29/55) of the animals that tested positively, FHV-1 alone was isolated from 38.2% (21/55) of the animals that tested positively, and co-infection were detected in 9.1% (5/55) of the animals that tested positively. Virus detection was more prevalent in cats that were less than 1 year old, among animals that shared a living space with other cats, and females. FCV and FHV-1 were isolated from vaccinated cats. In addition, both viruses were isolated from cats that showed no signs of disease. The results suggest that a carrier state is common for both viruses in the evaluated population. A search for other causes of respiratory disease in that population is necessary; and further studies relating to the molecular characterization of viruses and vaccine efficacy are also necessary.

Epidemiological status of felid herpesvirus type-1 and feline calicivirus infections in Brazil

“…The information available in Brazil consists of serological studies in wild and domestic cats (RUTHNER-BATISTA et al, 2005;FILONI et al, 2006;JOHANN et al, 2009;HENZEL et al, 2013), and isolation of FeHV-1 in RS (HENZEL et al, 2012b).…”

“…Furthermore, FeHV-1 was isolated from single infections or co-infections with FCV in 26 of 302 samples from the cat population of RS. Between the 26 isolates, 14 were derived from cats with respiratory signs and 12 from asymptomatic felines (HENZEL et al, 2012b).…”

“…Our research group detected antibodies against FCV in 39.2% of the 630 serum samples derived from cities neighboring the UPF, UFSM and UFRGS (HENZEL et al, 2013). Furthermore, FCV isolation and characterization in FeHV-1 single or mixed infections was reported in 34 of 55 positive cats in the virus isolation conducted on 302 swab samples, and such infections were more frequent in animals without clinical signs (HENZEL et al, 2012b). However, FCV has been isolated from 18 cats without any clinical manifestation at the time of collection and 4 cats with FeHV-1 co-infection confirmed by PCR (HENZEL et al, 2012b).…”

“…These studies have shown that approximately 10% of the populations of domestic cats are vaccinated (JOHANN et al, 2009;HENZEL et al, 2012b;HENZEL et al, 2013).…”

“…However, the isolation rates have not decreased since then furthermore; URTD remains responsible for high levels of morbidity and mortality in young cats (GASKELL & KNOWLES, 1989). The viruses are distributed worldwide and have been isolated in Brazil in the State of Rio Grande do Sul [RS] (WEIBLEN et al, 1988;HENZEL et al, 2012b). Serological studies on domestic and wild cats have been performed in RS and in the West-Central region of Brazil (RUTHNER-BATISTA et al, 2005;JOHANN et al, 2009;HENZEL et al, 2013).…”